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By J. M. Kuchta

Bench-scale test methods were developed by the Bureau of Mines for use by the Department of Transportation in the classification of solid and liquid oxidizers. A burning rate test is recommended for evaluating the fire hazard of solid inorganic oxidizers when mixed with a red oak sawdust as the reference combustible. A spontaneous ignition test is proposed for evaluating liquid and solid inorganic oxidizers which may decompose violently or ignite spontaneously when unmixed or mixed with the wood sawdust under unconfined conditions. Test results are compared for various representative oxidizers and a classification system is proposed for use in the government transportation regulations.

Jan 1, 1972

By Madan B. Karkee

The understanding and the development of sound theoretical basis concerning the pile foundations has been phenomenal during the past few decades, considering the thousands of years the piles have evidently been in use. The importance of the quality assurance and the need for verification of load bearing capacity is being further reinforced rather than undermined by these developments. This is evidenced by significant developments made in the pile load test technology in recent decades, making it possible to make judicious selection of a test method, or a package of test methods, suitable for a given situation. The selection depends on the objective of carrying out the test and the reliability desired. Presently, the possible selection ranges from dynamic to static methods. The extent of dynamic effect in a test can be reckoned based on a dimensionless parameter defined as the 'relative duration'. Examples of different load tests are given for illustration of the different methods currently in use.

Jan 1, 1997

By James C. Patterson

Sintered fly ash was shown to have promise as a modifier for poorly drained soils. Turf grown in mixtures of sintered fly ash and soil benefited from increased water-infiltration rates, greater total pore space, and higher moisture availability, The result was an improved turf stand with increased grass yield and root density.

Jan 1, 1970

By Dan Brown

This paper presents a case study of a cyclic lateral pile load testing program performed on two 18-in square prestressed concrete piles (PSC) in Savannah, Georgia. The load test program was developed to simulate the lateral behavior of a single pile under seismic loading conditions for the design and construction of a large LNG storage tank. The lateral load tests included cyclic loading to measure possible degradation in soil response followed by static loading to large displacements (around 6 inches at the loading point). The lateral load was applied through a reciprocating jack positioned to push and pull the piles against each other. The test piles were instrumented with multiple displacement transducers, downhole inclinometer, and strain gauges. This paper provides an interpretation of the test results regarding the pile performance and soil response to monotonic and cyclic lateral loading. A backfitted computational model of the soil resistance was developed to match the test results using the LPILE computer program. The load-deflection and deflection/moment versus depth comparisons suggest that this model appears to capture the behavior relatively well within the general range of suitability for design purposes. New design curves were developed based on the soil parameters derived from the lateral load test results.

Jan 1, 2003

By Sam S. Taylor

Subsurface disposal of oil-field brines was practiced in Oklahoma on a limited scale as early as 1925. The technique of subsurface injection has been improved immensely and has been applied with varying success in many oil-producing areas in Oklahoma, and elsewhere. This method of disposal, however, is only one of several methods available to operators of oil-producing properties, but, in contrast with usual methods of handling brines on the surface it eliminates the damaging effect of mineralized water on fresh-water supplies, vegetation, and aquatic and other animal life. Other methods of brine disposal approved by regulatory agencies in some States include (1) impounding in impervious ponds and solar evaporation, (2) controlled diversion into surface waters, and (3) recovery of the mineral salts of the brine. In most States where oil is produced regulatory bodies authorize the use of one or more of these methods of brine disposal. In Oklahoma, for example, the .Oklahoma Planning and Resources Board of the Conservation Commission has been authorized4/ to adopt whatever methods or means may be necessary to prevent contamination by mineralization of all potable waters within the State.

Jan 1, 1942

By Harpal Parmar

This paper evaluates dynamic methods of pile capacity prediction by comparing their results to static load test results. Dynamic and static pile load test data were assembled from four southeastern states of the U.S. End-of-drive and restrike capacities were evaluated using the Pile Driving Analyzer (PDA) and by wave equation (WEAP) analyses. These were compared to static (Davisson criterion) loads. The best comparison was obtained for restrike PDA results; restrike wave equation analyses values also compared well. The end-of-drive results for both methods-showed relatively poor comparisons. The PDA was recognized as an important tool to measure energy transferred to the pile; this transferred energy was recognized as an uncertainty when conducting wave equation analyses. A statistical analysis showed restrike capacity results to be associated with higher precision and accuracy as compared to end-of-drive methods. The authors believe that restrike dynamic testing is essential to establish long term static soil strength and that it will lead to accurate and cost-effective design of piles.

Jan 1, 1996

As mine haulage vehicles become larger, the danger to a driver during a fire emergency is increased by the greater height of the cab above ground. Also, property damage due to fires on bigger trucks can be substantial. To solve this problem, the Department of Interior's Bureau of Mines, through two research and development contracts with FMC Corporation, San Jose, California, has developed two reasonably priced, reliable automatic fire sensing and suppression prototype systems for large haulage vehicles. At the onset of the large mobile equipment fire protection contract effort, it was learned that fires were frequently experienced in open-pit mine haulage equipment, especially large trucks. As the size of equipment has grown, so has the hazard presented to an operator forced to leave his truck in a hurry when fire breaks out and his normal path to the ground is blocked by flames. His only recourse is to jump from the cab platform to the ground, and the one-story drop of 10 feet or more can severely injure him. It is with these factors in mind that a program was undertaken to provide a fire detection and extinguishing capability tor the large mobile equipment, especially trucks, used in open pit mines.

Jan 1, 2012

By K Cameron, S Strohmayr, J Wallace

In 2012, a single module heavy medium cyclone plant (HMP) was installed at the Glencore Zinc’s (then Xstrata Zinc) McArthur River lead zinc mine. The HMP formed the first part of the MRM Phase 3 Project to increase run of mine (ROM) capacity from 2.4 to 5.5 Mt/a.The purpose of the HMP is to remove liberated gangue from the crusher product at minimal loss of valuable mineral. The McArthur ores are very finely disseminated requiring a fine primary grind size prior to rougher flotation. Rejecting waste prior to grinding therefore offers significant power and grinding media savings. The plant was designed to treat only those ores with a reasonable upgrade ratio at the target zinc recovery across the HMP of 95%.On this basis, a 1.8 Mt/a single module plant was built based on 250 t/h feed rate and 82% availability. In contrast to existing base metal heavy medium plants in Australia, the MRM Flow sheet utilised the principles in modern coal heavy medium cyclone plant design. Since commissioning, the plant feed rate has been significantly increased and is now normally operated up to 540 t/h (dry basis).Although this throughput increase is partially due to debottlenecking work, it is also attributable to the conservative design parameters for base metal heavy medium cyclone circuits in comparison to those used in equivalent coal circuits.This paper discusses Flow sheet design and compares traditional base metal design parameters with those achieved at MRM and those of modern coal plants. It provides information on plant capital and operating costs and the net savings realised by its installation. In addition to power and grinding cost savings, the paper also highlights the savings in water through rejection of near dry waste and reduction of tailings pumped to the storage dam.CITATION:Wallace, J, Strohmayr, S and Cameron, K, 2015. McArthur River Mine heavy medium plant – the benefits of applying modern coal plant design principles to base metal heavy medium separation, in Proceedings MetPlant 2015, pp 311–323 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015

By T. McCallum

Crud is a common concern in SX processes and is formed as a complex solid stabilized emulsion of aqueous and organic.1,3 Crud formation is highly dependent on the amount of solids entering the circuit and is influenced by a number of other operational factors. A common practice for crud processing is interfacial pumping, wherein crud, organic, and aqueous are pumped from the settlers for treatment and utilizes a variety of equipment. These mechanical means of crud processing are effective, however, require significant processing time and require oversight to prevent the return of contaminated organic. Cytec has developed a unique crud treatment process utilizing both chemical and mechanical means to enhance the solid/liquid separation. The use of ACORGA CB? 1000 crud busting reagent allows a rapid separation of solids from the organic phase and provides similar volume recovery to current practices. The process allows operations to return clean organic back to the plant more efficiently and may enable operations to process more crud. In addition, the organic quality of the recovered organic is higher than that recovered by typical means, which can lead to operational cost savings.

Feb 27, 2013

By S. Bellec

A leaching model for gold ore that takes into account the impact of cyanide and oxygen concentrations as well as gold surface exposure on leaching performance is developed. Cyanide consumption is estimated by an empirical model that is a function of ore particles size distribution as well as cyanide, copper and sulphur concentrations. The proposed model has been validated by data from laboratory leaching tests on the Sleeping Giant gold mine ore. Keywords: gold leaching, modelling, exposure surface.

Jan 1, 2009

By J. L. Holman

The Bureau of Mines has extended its previous development of cast Mn-Cu damping alloys to powder metallurgy (P/M) consolidation of alloys containing 55 to 75 wt-pct Mn. Blends of minus 200-mesh elemental powders were compacted cold in directional and isostatic presses. With 1 pct binder, typical green densities ranged between 76 and 80 pct of theoretical when pressing at 30 or 48 tsi. Green strength increased with compacting pressure and copper content. As-sintered tensile strengths ranged to 60,000 psi fox a hydrogen, sintered 60Mn-40Cu alloy, along with 5-pct elongation. Sintered densities ranged between 90 and 96 pct of theoretical. Sintering (a as effective when holding for 1 hr at maximum temperatures of 900° to 1,040` C, dependent on composition. Strength and ductility were considerably lower than for equiva¬lent cast alloys. When aged to the damping condition, alloys containing 60 to 70 pct Mn exhibited >40 pct specific damping capacity (SDC) at 5,000-psi stress, considerably higher than values reported for equivalent cast material. Effects of 1 or 3 pct Sn or Zn additions on SDC and other properties were assessed. Trials were conducted on consolidating rings and gears of the 65Mn-35Cu alloy on industrial-type P/M equipment.

Jan 1, 1979

By Bruce Vandenberg

Two tests were set up as part of the course given by Blasting Analysis International. Both tests were performed using the prototype Velocity of Detonation Recorder (VODR). The prototype has several limitations, which have been rectified for the production units.

Jan 1, 1990

By J. Crummy, I. K. Anderson, A. J. Hall, R. S. Haszeldine

Bedrock gold mineralisation has been located in association with an extensive float train 25 km west of known alluvial gold. It is in the form of open, matrix-supported breccias comprising pyritic quartz/sericite clasts in a vuggy, cherty chalcedonic and crystalline quartz matrix. Fluid inclusions in pyritic clasts indicate trapping temperatures for gold mineralising hydrothermal fluid of 170-240 degrees C. This mineralisation could represent the upper part of a feeder zone to an exhalative hydrothermal system. It is possible that other high-level feeder zones could be preserved elsewhere in the area. Deep weathering of such a system could provide a source for the alluvial gold localities near Helmsdale. It is suggested that east and central Sutherland presents good prospects for exhalative epithermal gold mineralisation and the associated feeder zones

Jun 19, 1905

By Harold P. Rue

The problem of removing hydrogen sulphide from natural gas has become within the last few years one of major importance to the natural gas and petroleum industry. Several gas fields in the United States produce natural gas containing hydrogen sulphide, and a number of oil fields produce gas which contains hydrogen sulphide. 3 The percentage of hydrogen sulphide in natural gas produced in these fields varies from a fraction of 1 per cent t6 as high as 20.5 per cent by volume. 4 Hydrogen sulphide is probably the most toxic gas associated with natural gas,5 and from the standpoint of health and safety it is important that the hydrogen sulphide be removed if the gas is to be used for domestic purposes. Hydrogen sulphide, besides being toxic and therefore a hazard to animal life, is under certain conditions an active corrosive agent and very destructive to equipment. 6 The annual loss caused by the corrosive action of hydrogen sulphide on equipment amounts to hundreds of thousands, perhaps millions, of dollars. 7 The largest percentage of natural gas produced in the United States comes from wells which also produce oil. This associated gas invariably carries with it light fractions of petroleum, which when separated from the gas, condense to the liquid form at ordinary temperatures and pressure. Commercial application is made of this natural condition, and "wet gas" is processed to obtain so-called natural gasoline by employing the principles of absorption, adsorption, or compression and subsequent expansion accompanied by cooling. In the manufacture of natural gasoline from wet gas which contains hydrogen sulphide, if this contaminating gas is not first removed, some of the hydrogen sulphide may oxidize to form free

Jan 1, 1932

By A. H. Mokken

Failed attempts at amalgamation of a gold/osmiridium concentrate, recovered behind pebble mill liners during re-lining, led to the discovery that the gold particles were coated and that nitric acid only could remove the coatings. Following this treatment amalgamation was rapid and resulted in a complete recovery of the gold that otherwise would have been lost in plant residues. Investigations into the nature and formation of the coatings led to the realization that the coatings were impregnations of harder elements, associated with the gold during grinding and driven into the softer gold surface by high pressure, impact and attrition. It was further realized that this phenomenon could be part of gold ore milling, world-wide. With these thoughts in mind the question is asked whether concentration down to micron sizes prior to cyanidation, should not play a greater role in gold recovery.

Jan 1, 1999

Entry of personnel under a vertical raise bored hole is not standard practice in Australia. Where access is required below a rise, mining operations must be confident that they understand the capacity of the ground control specified and installed. Physical modelling was conducted on Callie mine to evaluate the performance of 5 mm steel wire weldmesh secured to the base of a vertical raise bored hole of 1.4 m diameter. Joint orientation data was used with Unwedge to calculate a series of potential wedges likely to form within the rise. The mass of the most likely wedges were then replicated by collecting rocks in 5 kg increments (¦10 per cent), which were allowed to freefall onto installed mesh at the base of a 40 m vertical rise. The results indicate that two sheets of mesh can retain a freefalling rock of at least 20 kg mass although rupture of strands can result. This paper outlines the test conditions, expected results based on theoretical calculations and actual outcomes of the testing.

Nov 25, 2010

By Louis Schaffer

The objectives of the research were to determine whether a model health and safety program could be defined in terms which would enable its application to mines of all types, and, if such a model program could be defined, to determine through evaluations in two mining companies whether it would achieve measurable improvements. Volume 1 describes the model, how it was applied in the field and how it was evaluated. This, Volume 2, describes the literature and field research that preceded the model definition.

Jan 1, 1983

By C. Birch

"A mineral resource royalty is payment to the holder of mineral rights for the utilization of the mineral resource. In South Africa, this payment is made to the State as holder of the mineral rights (The Mineral and Petroleum Resources Royalty Act of 2008). The principle purpose of this research paper is to identify if the State is benefitting from the mineral resource royalty by considering its impact on seven individual Witwatersrand gold mines.For this study, a simple financial optimiser model was created in Microsoft Excel that links the ore flow, block listing and the cash flow (excluding or including the cost of the mineral resource royalty). Mixed integer linear programing (the Excel Solver function) is utilised to optimise either profit or NPV (at 9% and 12%) by adjusting the cut-off grade.The impact on each of the seven mines mine was different but overall R7.9 billion is estimated to be paid in mineral resource royalty over their expected remaining lives. Due to the cost of the mineral resource royalty and increasing the cut-off grades, the total revenue decreases by R10 billion. A significant portion of this lost revenue would have been paid to the State in the forms of other taxation including company income tax which decreases by R2.8 billion. It is recommended that an industry wide investigation be conducted to determine if the resource royalty is adding to the State’s revenue, or destroying value including premature job losses. IntroductionTaxation of mining companies has become a very topical subject in the context of the postapartheid South African economy. There have been increasing calls for equitable re-distribution of mineral asset wealth for the benefit of all South African citizens and not just to an elite few. As part of the Mineral and Petroleum Resources Development Act (MRDPA) of 2002, the Mineral and Petroleum Resources Royalty Act of 2008 was introduced and came into effect in 2010 (South African Revenue Services, 2008). A mineral royalty is payment to the holder of mineral rights for the utilization of the mineral resource. In the case where the holder of the mineral right is the State, then this payment is made to the State (Cawood, 1999). Studies on the potential impact of the mineral resource royalty on the minerals industry have been conducted during the formulation of the Act and subesquently. These include Cawood and Macfarlane (2003), who suggested a cap of no more than 3% (Cawood and Macfarlane, 2003), as well as Cawood (2011), who predicted rising cut-off grades and thus reducing mineral reserves. In 2013, Grobler completed a Masters in the Faculty of Economic and Management Sciences at the University of Pretoria and concluded that the impact of the mineral resource royalty on the economy is positive. She stated that the royalty has caused operating expenses to increase, but this does not appear to be significant. Furthermore, she stated that the royalty has not affected the way the mining industry operates (Grobler, 2014)."

Jan 1, 2016

By Xuejing Xie, Tianxiang Ren

Paper presented at the 28th International Geological Congress held in Washington DC, July 1989 (International geochemical mapping sessions). Standardised stream-sediment sampling procedures have been used in mountainous and hilly terrains. Special sampling procedures were developed for application in remote environments, such as high mountains, desert, semi-desert, karst and loess-covered regions. The diversified analytical methods used in more than 20 analytical laboratories participating in the project have been unified into two multi-element, multi-method analytical systems. A unified data monitoring procedure was developed based on primary and secondary standard samples. To date the project has covered about 4 000 000 km2 and the aim is to complete the coverage within the present decade

May 1, 1991

The latest Draft MPRRB was released for public comment in October 2006. The main purpose of the Bill is to collect royalties at mines developed in terms of new-order mineral rights granted through the MPRDA process. The transition phase stipulated in the MPRDA will be completed by 1 May 2009, on which date mineral royalties will become payable to the state. The royalty rates stated in the MPRRB differ from mineral to mineral and also depend on the degree of refinement. Gold is the subject of this paper, where the royalty rate ranges from 1.5% (for refined gold) to 3% (for unrefined gold) of sales revenue. This royalty is payable regardless of profit, with a maximum 75% relief for loss-making mines. The purpose of this paper is to establish whether or not it would be necessary for gold mines to adjust their mineral reserve statements as a result of this Bill. The methodology is to add the royalty costs stipulated in the MPRRB to the actual quarterly information for the past ten years as reported by the gold-mine members of the COM. The rationale is to investigate the impact this Bill (in its current form) would have had on gold reserves that must be left unmined in the ground because of a higher pay limit. The results of the study point to a significant impact on reserves available for mining with the subsequent shortening of mine lives and retrenchment of workers. Had the MPRRB been effective for the 10 years prior to 1996, it would have resulted in 46 tonnes of gold being sterilised. Stated alternatively, 30 700 workers at COM gold mines alone would have lost their livelihoods.

Jan 1, 2007